EP1.49 Outcomes of femoral osteotomy with and without concurrent pelvic osteotomy: a study from the UK Non-Arthroplasty Hip Registry

Abstract

Abstract Background Femoral osteotomy (FO) is performed for a heterogeneous range of paediatric and adult hip pathology, and is frequently combined with a concurrent pelvic osteotomy. The relative outcomes of isolated FO, versus FO performed alongside a periacetabular osteotomy (PAO), or alongside another pelvic osteotomy are not well described. We used the UK Non-Arthroplasty Hip Registry (NAHR) to compare patient-reported outcomes across these three groups. Methods All primary FO procedures recorded in NAHR between January 2012 and January 2025 were identified. Cases were classified into three groups: (1) isolated FO, (2) FO + PAO, and (3) FO + other pelvic osteotomy. Patients aged <16 years, revisions, and those without a pre-operative iHOT-12 or any post-operative questionnaire (6- or 12-month) were excluded. Femoral osteotomy components (derotation, varus, valgus, shortening, complex, trochanteric advancement, open reduction, other) were tabulated per group. The primary outcome was change in iHOT-12 score at 12 months. Secondary outcomes included EQ-5D Index and EQ-5D VAS. Results 94 cases met eligibility (Isolated FO n=54, FO + PAO n=33, FO + other PO n=7; all 'other PO' were pelvic triple osteotomies). Mean age was 27.2 years (SD 7.0) and 80% were female. FO + PAO patients were significantly younger (24.0 vs 28.9 vs 29.3 years; p=0.004). The two most common FO components were derotation (83%) and 'other' (9%) in the isolated FO group; derotation (58%) and trochanteric advancement (33%) in the FO + PAO group; and derotation (100%) alone in the FO + other PO group. Pre-operative iHOT-12 differed across groups (median 24, 33, and 16; p=0.009). At 12 months, mean iHOT-12 improvement was clinically and statistically significant within the isolated FO (+16.5, 95%CI 7.5–25.6; p<0.001) and FO + PAO (+20.8, 95%CI 10.9–30.7; p<0.001) groups, with a similar magnitude in the FO + other PO group (+16.0, 95%CI -2.5–34.5) although limited by sample size. There was no significant difference in 12-month iHOT-12 change between groups (p=0.78). Conclusions In this national cohort, femoral osteotomy delivered clinically meaningful improvements in hip-specific patient-reported outcomes whether performed in isolation or alongside a concurrent PAO or other pelvic osteotomy, with no significant between-group difference in 12-month iHOT-12 improvement.